From nobody Tue May 21 00:06:51 2024 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6ABC3C636D3 for ; Wed, 8 Feb 2023 18:09:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230307AbjBHSJL (ORCPT ); Wed, 8 Feb 2023 13:09:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231473AbjBHSJJ (ORCPT ); Wed, 8 Feb 2023 13:09:09 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8E701BED for ; Wed, 8 Feb 2023 10:09:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 15F7CB81F05 for ; Wed, 8 Feb 2023 18:09:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21AC6C433EF; Wed, 8 Feb 2023 18:09:02 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="WofiAhnz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1675879739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=GaxZEkIUD+daqbPo0K2RaJyv+NKHeTeHop2uRO4qC9o=; b=WofiAhnzBnh+i5V5dr48vx5vCPG2u9XMpovr5EEReYbNBiKSPNHPUsUyTgyBbiLjK7uR1L d2jO+GrKs4OaQS1pjdCtDf+P8nMJSGdxuMdSIIohH2WuZhGEnkkiPy8tJiEPSbtsW7lpIH qtIbKauAX0XLVHXWPNnVW/spaImv/SY= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 1d3bfabc (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 8 Feb 2023 18:08:58 +0000 (UTC) From: "Jason A. Donenfeld" To: qemu-devel@nongnu.org Cc: x86@kernel.org, linux-kernel@vger.kernel.org, "Jason A. Donenfeld" , "Michael S . Tsirkin" , Dov Murik , Tom Lendacky , Gerd Hoffmann , =?UTF-8?q?Daniel=20P=20=2E=20Berrang=C3=A9?= , Paolo Bonzini , Richard Henderson , "H . Peter Anvin" , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Nathan Chancellor , Borislav Petkov , Eric Biggers Subject: [PATCH] x86: temporarily remove all attempts to provide setup_data Date: Wed, 8 Feb 2023 15:08:35 -0300 Message-Id: <20230208180835.234638-1-Jason@zx2c4.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All attempts at providing setup_data have been made as an iteration on whatever was there before, stretching back to the original implementation used for DTBs that [mis]used the kernel image itself. We've now had a dozen rounds of bugs and hacks, and the result is turning into a pile of unmaintainable and increasingly brittle hacks. Let's just rip out all the madness and start over. We can re-architect this based on having a separate standalone setup_data file, which is how it should have been done in the first place. This is a larger project with a few things to coordinate, but we can't really begin thinking about that while trying to play whack-a-mole with the current buggy implementation. So this commit removes the setup_data setting from x86_load_linux(), while leaving intact the infrastructure we'll need in the future to try again. Cc: Michael S. Tsirkin Cc: Dov Murik Cc: Tom Lendacky Cc: Gerd Hoffmann Cc: Daniel P. Berrang=C3=A9 Cc: Paolo Bonzini Cc: Richard Henderson Cc: H. Peter Anvin Cc: Philippe Mathieu-Daud=C3=A9 Cc: Nathan Chancellor Cc: Borislav Petkov Cc: Eric Biggers Signed-off-by: Jason A. Donenfeld Tested-by: Nathan Chancellor --- hw/i386/microvm.c | 15 ++---- hw/i386/x86.c | 120 +++++----------------------------------------- 2 files changed, 17 insertions(+), 118 deletions(-) diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c index 29f30dd6d3..170a331e3f 100644 --- a/hw/i386/microvm.c +++ b/hw/i386/microvm.c @@ -378,8 +378,7 @@ static void microvm_fix_kernel_cmdline(MachineState *ma= chine) MicrovmMachineState *mms =3D MICROVM_MACHINE(machine); BusState *bus; BusChild *kid; - char *cmdline, *existing_cmdline; - size_t len; + char *cmdline; =20 /* * Find MMIO transports with attached devices, and add them to the ker= nel @@ -388,8 +387,7 @@ static void microvm_fix_kernel_cmdline(MachineState *ma= chine) * Yes, this is a hack, but one that heavily improves the UX without * introducing any significant issues. */ - existing_cmdline =3D fw_cfg_read_bytes_ptr(x86ms->fw_cfg, FW_CFG_CMDLI= NE_DATA); - cmdline =3D g_strdup(existing_cmdline); + cmdline =3D g_strdup(machine->kernel_cmdline); bus =3D sysbus_get_default(); QTAILQ_FOREACH(kid, &bus->children, sibling) { DeviceState *dev =3D kid->child; @@ -413,12 +411,9 @@ static void microvm_fix_kernel_cmdline(MachineState *m= achine) } } =20 - len =3D strlen(cmdline); - if (len > VIRTIO_CMDLINE_TOTAL_MAX_LEN + strlen(existing_cmdline)) { - fprintf(stderr, "qemu: virtio mmio cmdline too large, skipping\n"); - } else { - memcpy(existing_cmdline, cmdline, len + 1); - } + fw_cfg_modify_i32(x86ms->fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(cmdline) = + 1); + fw_cfg_modify_string(x86ms->fw_cfg, FW_CFG_CMDLINE_DATA, cmdline); + g_free(cmdline); } =20 diff --git a/hw/i386/x86.c b/hw/i386/x86.c index eaff4227bd..6cfdca9acd 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -50,7 +50,6 @@ #include "hw/intc/i8259.h" #include "hw/rtc/mc146818rtc.h" #include "target/i386/sev.h" -#include "hw/i386/microvm.h" =20 #include "hw/acpi/cpu_hotplug.h" #include "hw/irq.h" @@ -770,30 +769,6 @@ static bool load_elfboot(const char *kernel_filename, return true; } =20 -typedef struct SetupDataFixup { - void *pos; - hwaddr orig_val, new_val; - uint32_t addr; -} SetupDataFixup; - -static void fixup_setup_data(void *opaque) -{ - SetupDataFixup *fixup =3D opaque; - stq_p(fixup->pos, fixup->new_val); -} - -static void reset_setup_data(void *opaque) -{ - SetupDataFixup *fixup =3D opaque; - stq_p(fixup->pos, fixup->orig_val); -} - -static void reset_rng_seed(void *opaque) -{ - SetupData *setup_data =3D opaque; - qemu_guest_getrandom_nofail(setup_data->data, le32_to_cpu(setup_data->= len)); -} - void x86_load_linux(X86MachineState *x86ms, FWCfgState *fw_cfg, int acpi_data_size, @@ -803,29 +778,20 @@ void x86_load_linux(X86MachineState *x86ms, bool linuxboot_dma_enabled =3D X86_MACHINE_GET_CLASS(x86ms)->fwcfg_dma= _enabled; uint16_t protocol; int setup_size, kernel_size, cmdline_size; - int dtb_size, setup_data_offset; uint32_t initrd_max; uint8_t header[8192], *setup, *kernel; - hwaddr real_addr, prot_addr, cmdline_addr, initrd_addr =3D 0, first_se= tup_data =3D 0; + hwaddr real_addr, prot_addr, cmdline_addr, initrd_addr =3D 0; FILE *f; char *vmode; MachineState *machine =3D MACHINE(x86ms); - SetupData *setup_data; const char *kernel_filename =3D machine->kernel_filename; const char *initrd_filename =3D machine->initrd_filename; - const char *dtb_filename =3D machine->dtb; - char *kernel_cmdline; + const char *kernel_cmdline =3D machine->kernel_cmdline; SevKernelLoaderContext sev_load_ctx =3D {}; enum { RNG_SEED_LENGTH =3D 32 }; =20 - /* - * Add the NUL terminator, some padding for the microvm cmdline fiddli= ng - * hack, and then align to 16 bytes as a paranoia measure - */ - cmdline_size =3D (strlen(machine->kernel_cmdline) + 1 + - VIRTIO_CMDLINE_TOTAL_MAX_LEN + 16) & ~15; - /* Make a copy, since we might append arbitrary bytes to it later. */ - kernel_cmdline =3D g_strndup(machine->kernel_cmdline, cmdline_size); + /* Align to 16 bytes as a paranoia measure */ + cmdline_size =3D (strlen(kernel_cmdline) + 16) & ~15; =20 /* load the kernel header */ f =3D fopen(kernel_filename, "rb"); @@ -966,6 +932,12 @@ void x86_load_linux(X86MachineState *x86ms, initrd_max =3D x86ms->below_4g_mem_size - acpi_data_size - 1; } =20 + fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr); + fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(kernel_cmdline) + 1= ); + fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline); + sev_load_ctx.cmdline_data =3D (char *)kernel_cmdline; + sev_load_ctx.cmdline_size =3D strlen(kernel_cmdline) + 1; + if (protocol >=3D 0x202) { stl_p(header + 0x228, cmdline_addr); } else { @@ -1078,81 +1050,13 @@ void x86_load_linux(X86MachineState *x86ms, } fclose(f); =20 - /* append dtb to kernel */ - if (dtb_filename) { - if (protocol < 0x209) { - fprintf(stderr, "qemu: Linux kernel too old to load a dtb\n"); - exit(1); - } - - dtb_size =3D get_image_size(dtb_filename); - if (dtb_size <=3D 0) { - fprintf(stderr, "qemu: error reading dtb %s: %s\n", - dtb_filename, strerror(errno)); - exit(1); - } - - setup_data_offset =3D cmdline_size; - cmdline_size +=3D sizeof(SetupData) + dtb_size; - kernel_cmdline =3D g_realloc(kernel_cmdline, cmdline_size); - setup_data =3D (void *)kernel_cmdline + setup_data_offset; - setup_data->next =3D cpu_to_le64(first_setup_data); - first_setup_data =3D cmdline_addr + setup_data_offset; - setup_data->type =3D cpu_to_le32(SETUP_DTB); - setup_data->len =3D cpu_to_le32(dtb_size); - load_image_size(dtb_filename, setup_data->data, dtb_size); - } - - if (!legacy_no_rng_seed && protocol >=3D 0x209) { - setup_data_offset =3D cmdline_size; - cmdline_size +=3D sizeof(SetupData) + RNG_SEED_LENGTH; - kernel_cmdline =3D g_realloc(kernel_cmdline, cmdline_size); - setup_data =3D (void *)kernel_cmdline + setup_data_offset; - setup_data->next =3D cpu_to_le64(first_setup_data); - first_setup_data =3D cmdline_addr + setup_data_offset; - setup_data->type =3D cpu_to_le32(SETUP_RNG_SEED); - setup_data->len =3D cpu_to_le32(RNG_SEED_LENGTH); - qemu_guest_getrandom_nofail(setup_data->data, RNG_SEED_LENGTH); - qemu_register_reset_nosnapshotload(reset_rng_seed, setup_data); - fw_cfg_add_bytes_callback(fw_cfg, FW_CFG_KERNEL_DATA, reset_rng_se= ed, NULL, - setup_data, kernel, kernel_size, true); - } else { - fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size); - } - - fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr); - fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, cmdline_size); - fw_cfg_add_bytes(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline, cmdline_= size); - sev_load_ctx.cmdline_data =3D (char *)kernel_cmdline; - sev_load_ctx.cmdline_size =3D cmdline_size; - + fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size); fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr); fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size); sev_load_ctx.kernel_data =3D (char *)kernel; sev_load_ctx.kernel_size =3D kernel_size; =20 - /* - * If we're starting an encrypted VM, it will be OVMF based, which use= s the - * efi stub for booting and doesn't require any values to be placed in= the - * kernel header. We therefore don't update the header so the hash of= the - * kernel on the other side of the fw_cfg interface matches the hash o= f the - * file the user passed in. - */ - if (!sev_enabled() && first_setup_data) { - SetupDataFixup *fixup =3D g_malloc(sizeof(*fixup)); - - memcpy(setup, header, MIN(sizeof(header), setup_size)); - /* Offset 0x250 is a pointer to the first setup_data link. */ - fixup->pos =3D setup + 0x250; - fixup->orig_val =3D ldq_p(fixup->pos); - fixup->new_val =3D first_setup_data; - fixup->addr =3D cpu_to_le32(real_addr); - fw_cfg_add_bytes_callback(fw_cfg, FW_CFG_SETUP_ADDR, fixup_setup_d= ata, NULL, - fixup, &fixup->addr, sizeof(fixup->addr)= , true); - qemu_register_reset(reset_setup_data, fixup); - } else { - fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr); - } + fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr); fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size); fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size); sev_load_ctx.setup_data =3D (char *)setup; --=20 2.39.1